Transcript

1.
Mohit Jha Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 6( Version 2), June 2014, pp.37-47
www.ijera.com 37 | P a g e
Design Of Interval Type-Ii Fuzzy Logic Traffic Controller For
Multilane Intersections With Emergency Vehicle Priority System
Using Matlab Simulation
Mohit Jha, Shailja Shukla
Department of Electrical Engineering, Jabalpur Engineering College, Jabalpur, M.P., India
Department of Computer Science Engineering, Jabalpur Engineering College, Jabalpur, M.P., India
Abstract
During the past several years fuzzy logic control has swell from one of the major active and profitable areas for
research in the application of fuzzy set, especially in the zone of industrial process which do not lead themselves
to control conventional methods because of lack of quantitative data regarding the input-output relations. Fuzzy
control is based on fuzzy logic- a logical system which is much closer in spirit to human thinking and natural
language than conventional logical systems. The fuzzy logic controller based on fuzzy logic provides a means of
converting a linguistic control strategy based on expert knowledge into an automatic control strategy. As in
Fuzzy logic traffic controller, the need arises for simulating and optimizing traffic control algorithms to better
accommodate this increasing demand. Fuzzy optimization deals with finding the values of input parameters of a
complex simulated system which result in desired output. This paper presents a MATLAB simulation of fuzzy
logic traffic interval type II controller for controlling flow of traffic in multilane paths. This controller is based
on the waiting time and queue length of vehicles at present green phase and vehicles queue lengths at the other
lanes. The controller controls the traffic light timings and phase difference to ascertain sebaceous flow of traffic
with least waiting time and queue length. In this paper, the multilane model used consists of two alleyways in
each approach. Every outlook has different value of queue length and waiting time, systematically, at the
intersection. The maximum value of waiting time and vehicle queue length has to be selected by using
proximity sensors as inputs to controller for the ameliorate control traffic flow at the intersection. An intelligent
traffic model and fuzzy logic interval type II traffic controller are developed to evaluate the performance of
traffic controller under different pre-defined conditions for oleaginous flow of traffic. Additionally, this fuzzy
logic traffic controller has emergency vehicle siren sensors which detect emergency vehicle movement like
ambulance, fire brigade, Police Van etc. and gives maximum priority to him and pass preferred signal to it.
Keywords-Fuzzy Traffic Controller; Multilane Intersection; Vehicle Actuated Controller; Emergency Vehicle
Selector, Fuzzy Interval type II.
I. INTRODUCTION
Fuzzy logic system (FLS) (also known as a fuzzy
system, fuzzy logic controller, etc) includes fuzzifier,
rules, inference engine, and defuzzyifier. Quite often,
the knowledge that is used to construct the rules in a
FLS is mutable .Today's conventional controllers,
which are developed based on recorded data to
ameliorate timing plans are no longer the fanciful
Solution to traffic intersections due to varying traffic
volumes with respect to time and also increasing
numbers of vehicles on road. Traffic controllers
which will be able to cogitate equal way of human
thinking are designed using Intelligence techniques
like fuzzy logic, neural networks, Genetic Algorithm,
Particle Swarm optimization(PSO), etc. The main
purpose of making new intelligent traffic controllers
is that the traffic controllers that have the overall
efficiency to accommodate to the present time data
from sensors or detectors to perform constant
command of interpreter on the signal timing plan for
multilane intersections in a network in order to reduce
traffic overcrowding which is the main anxiety in
traffic flows control now a day, at multilane traffic
intersections.
Quite often, the knowledge that is used to construct
the rules in a FLS is uncertain. Three ways in which
such rule uncertainty can occur are: 1) the words that
are used in antecedents and consequents of rules can
mean different things to different people ; 2)
consequents obtained by polling a group of experts
will often be different for the same rule because the
experts will not necessarily be in agreement; and 3)
noisy training data. Type-1 FLSs, whose membership
functions are type-1 fuzzy sets, are unable to directly
handle rule uncertainties. Type-2 FLSs, in which
antecedent or consequent membership functions are
type-2 fuzzy sets, can handle rule uncertainties.
General type-2 FLSs is computationally intensive
because type-reduction is very intensive. Things
RESEARCH ARTICLE OPEN ACCESS

2.
Mohit Jha Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 6( Version 2), June 2014, pp.37-47
www.ijera.com 38 | P a g e
simplify a lot when secondary membership functions
(MFs) are interval sets (in this case, the secondary
memberships are either zero or one and we call them
interval type-2 sets).
The most commonly used fuzzifier is a singleton;
but, such
a fuzzifier is not adequate when data is corrupted by
measurement noise. In this case, a non-singleton
fuzzifier that treats each measurement as a fuzzy
number should be used. The theory and applications
of a type-1 FLS with non-singleton fuzzifier are
presented in [27], where the input is fuzzified into a
type-1 fuzzy set (e.g., Gaussian) whose parameters
are based on the measured input and the mean and
variance of the measurement noise. This assumes that
the statistical knowledge (mean and variance) of the
noise is given or can be estimated; but, in many cases,
these values are not known ahead of time and cannot
be estimated from the data. Instead, we only have
some linguistic knowledge about the noise, such as
very noisy, moderately noisy, or approximately no
noise.
Human judgment making and Inference in traffic
and carriages are designate by a generally good
execution. Even if the judgment makers have
unfinished information and key judgment merits are
accurately or oracularly as stipulated or not described
at all, and the judgment taking goal are ambiguous,
the capacity of human judgment building is
remarkably. According to [1], traffic intersections
that are managed by human operators are still more
effective as compared to the traffic responsive control
and traditional methods. The older system uses
weight as a trigger mechanism Current traffic systems
react to motion to trigger the light changes [2].
Figure 1 Multilane Traffic Intersection
The first step-in-aid of fuzzy logic controller in
the history in 1977, which displays preferable
execution weigh to vehicle actuated controller for an
exclusively intersection have two one-way roadways
based on a green time extension principle. From this
persuasive work, the main attention for the research
has been initiated on petition for fuzzy control
methods for intersection control greatly focus at a
segregate multilane intersection. Modern traffic
signal controls use highly capable microprocessor
based algorithms to control vehicle movements
through intersections [3]. The utilization of fuzzy
logic controllers in juxtaposition with conventional
pre-timed or vehicle-actuated control modes has
provided improved traffic manipulation ethically to
the usually adopted execution measures as in the case
with delays and number of stops.. Fuzzy controllers
have perfectly demonstrated dominant in controlling
a single traffic intersection, even if the intersection is
in certain complex level. In somewhat illustration,
even if topical controllers perform nice, there is no
clearly warranty that they will continue to do so when
the intersections are concatenate with irregular traffic
flow. Now, further development took place by
accepting fuzzy logic based controllers on traffic
signal for two-way single intersection. In Traffic
signal multilane intersections, vehicle detection
sensors are linked together in order to form an
individual closed network [6].
In this research, extensive description on the
method used in designing the fuzzy logic interval
type II traffic signal controllers and the overall
project development are included. MATLAB is the
exclusive software program used in step-in-aid of the
whole project. The traffic signal controllers are
contemplated using SIMULINK block diagram
provided by MATLAB.
The Interval Type-2 Fuzzy Logic Toolbox
(IT2FLT) is a collection of functions built on the
MATLAB numeric computing environment. It
provides tools for you to create and edit Interval
Type- 2 Fuzzy Inference Systems (IT2FIS) within the
framework of MATLAB.
For fuzzy logic based traffic signal controller
system, Mamdani-Type fuzzy inference system (FIS)
editor is used to develop fuzzy rules, input and output
membership functions. Fuzzy traffic controller will
be constitute either using graphical user interface
(GUI) tools or working from the command line.
Interval type-2 fuzzy sets and fuzzy operators are
the subjects and verbs of interval type-2 fuzzy logic.
These if-then rule statements are used to formulate
the conditional statements that comprise intervaltype-
2 fuzzy logic. A single if-then interval type-2 fuzzy
rule assumes the form
if x is !A then y is !B
Where, !A and !B are linguistic values defined by
interval type-2 fuzzy sets on the ranges (universes of

3.
Mohit Jha Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 6( Version 2), June 2014, pp.37-47
www.ijera.com 39 | P a g e
discourse) X and Y, respectively. The if-part of the
rule “x is !A ” is called the antecedent or premise,
while the then-part of the rule “y is !B” is called the
consequent or conclusion. An example of such a rule
might be
In this project, the traffic model is developed
using SIMULINK model block diagram and extended
with the SimEvent block diagram. Nevertheless,
actuated traffic signal controller for multilane
intersection is developed in this project. This fuzzy
logic traffic controller work separately for emergency
vehicles like ambulance, fire-brigade and police van.
They give separate time interval for passing an
emergency vehicle from intersection according to
their movement. The intersection delay time, there
have been a variety of achievements in recent
years [4]. Lastly, the results from the simulations are
shown on waiting time, average delay time and queue
length and presence of emergency vehicle in queue as
execution index for controlling traffic flow at the
intersection.
II. MULTILANE TRAFFIC MODEL
The traffic signal controller for segregate
intersection is shown in Figure 1 is designed based
upon the normal traffic system for eight lane
intersection. The multilane traffic intersection model
developed in MATLAB using Simulink and SimEvent
toolbox is shown in Figure 2.
Figure 2 SIMULINK Block Diagram of Multilane
Traffic Intersection Model
There are four standpoints in this multilane
intersection model with sixteen total movements and a
server traffic light. Each standpoint consists of two
campaigns which are one through campaign and one
right turn campaign. This model is based upon
multiple input single output theory and is constructing
based on three main desired concepts in queuing
theory which are customers, queue, and servers.
There is one more queue model discipline is
applied on all stand points that is first-come-first-out
(FIFO). From queuing theory point of view, the
vehicles are like customers in this model while
services time is the waiting time to get off from
intersection.
Figure 3 SIMULINK Block Diagram of Traffic Proximity
Sensors
Traffic arrival rate and service times of vehicle at
the intersection are independent random variables
with Poisson distribution which means that vehicles
arrival rate at the intersection is Poisson process with
arrival rate λ and the mean of the inter-arrival rate
times between vehicles are 1/λ. The arrival vehicle is
a Poisson process and the numbers of arrival of
vehicles in a system is a Poisson distribution.
Function as shown by Equation 1.
𝑝 𝑞𝑖𝑛 𝑡 = 𝑘 =
(𝜆∆𝑡) 𝑘
𝑒−𝜆∆𝑡
𝑘!
(1)
Where, λ is greater than 0 is the arriving rate
which is equivalent to the number of arrived vehicles
per time period and k=0, 1, 2, ….
III. DESIGN OF FUZZY LOGIC INTERVAL
TYPE II TRAFFIC CONTROLLER
For this project fuzzy logic interval type II traffic
controller is designed using MATLAB Toolbox. The
design has been divided into three stages which are
Green Phase stage, next phase stage, switching stage.
The design structure of fuzzy logic segregate traffic
intersection model controller is shown in Figure 4.
A. Green Phase Stage
The real time traffic conditions of the green phases
are supervised by the Green Phase Stage. Green phase
magnitude value for real time is produced by this
stage according to the present condition observed by
traffic flow using proximity sensors on both side of

4.
Mohit Jha Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 6( Version 2), June 2014, pp.37-47
www.ijera.com 40 | P a g e
lane. Fuzzy logic controller block and embedded
MATLAB function block that contain C programming
codes are the two main blocks of this stage. This stage
contain "Fuzzy Controller block" which has one set of
Mamdani Type fuzzy inference system which is used
to evaluate green signal extension time on real time. In
this fuzzy controller there is set of 25 rules and fuzzy
inference system this rules takes the value of vehicles
waiting time and the vehicle queue length at real time
at green phase and creates extension time value as an
output. This value is sent to "Embedded MATLAB
function" block for assessment. This block contain if-
else statement which finds the real probability that the
green phase need to extend based on the generated
output from the fuzzy inference system and the queue
length of the other three phases.
Figure 3 SIMULINK Block Diagram of Traffic
Proximity Sensors
Queue length (QL) and waiting time (Wt) are
consumed as the two input variables for fuzzy
inference system in traffic controller using proximity
sensors which is shown in Figure 3. This system
contains input membership function, fuzzy set rules
and output membership function. Here, in both input
and output membership function itritype2 type
membership function is used in place of triangular
membership function because traffic does not change
linearly in real time. The range of vehicle waiting time
is assumed to be 50seconds which is divided into five
different ranges: very short (VS), short (S), long (L),
very long (VL), and extremely long (EL).
Each range coincides to a membership function.
Also there are five ranges of membership functions in
vehicle waiting time (Wt). All of these have standard
deviation (𝜎) of 2 and the constant for itritype2
membership function of very short (VS), short (S),
long (L), very long (VL), and extremely long (EL) are
of 0seconds, 10 seconds, 20 seconds, 30 seconds, and
40 seconds, respectively.
Similarly, for the vehicle queue length (QL), the
range is assumed to be 0 to 50 vehicles in a lane on
each approach at the intersection. The input to a
vehicle queue length (QL) membership function is
very short (VS), short (S), long (L), very long (VL),
and extremely long (EL). All of these have standard
deviation (𝜎) of 2 and the constant for Gaussian
membership function of very short (VS), short (S),
long (L), very long (VL), and extremely long (EL) are
of 0vehicles, 10 vehicles, 20 vehicles, 30 vehicles, and
40 vehicles, respectively.
The output fuzzy variable span which means
extended time of green signal light is divided into 5
ranges analogous to fuzzy sets: zero (Z), short (S),
long (L), very long (VL), and extremely long (EL).
All these membership functions are Gaussian type
with standard deviation (𝜎) of 2 and constant, c which
is equals to 2.5.Fuzzy logic controller is designed with
rule base using IF-THEN conditions. Mainly, fuzzy
rules system is developed with IF-AND-THEN
statements. The fuzzy logic rule base traffic signal
controller at segregate intersection is defined is
TABLE 1. Here, used Interval Type-2 Fuzzy
inference is the process of formulating the mapping
from a given input to an output using interval type-2
fuzzy logic [4]. The mapping then provides a basis
from which decisions can be made, or patterns
discerned
There are two types of fuzzy inference systems
that can be implemented in the Interval Type-2 Fuzzy
Logic Toolbox: Mamdani-type [4, 6, 9] and Sugeno-
type [4, 5, 7]. These two types of inference systems
vary somewhat in the way outputs are determined.

5.
Mohit Jha Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 6( Version 2), June 2014, pp.37-47
www.ijera.com 41 | P a g e
Interval Type-2 Fuzzy inference systems have
been successfully applied in fields such as automatic
control, data classification, decision analysis, expert
systems, and computer vision [4]. Because of its
multidisciplinary nature, interval type-2 fuzzy
inference systems are associated with a number of
names, such as interval type-2 fuzzy-rule-based
systems, interval type-2 fuzzy expert systems,
interval type-2 fuzzy modeling, interval type-2 fuzzy
associative memory, interval type-2 fuzzy logic
controllers, and simply (and ambiguously) interval
type-2 fuzzy systems.
Mamdani-type interval type-2 fuzzy inference, as
we have defined it for the Interval Type-2 Fuzzy
Logic Toolbox [1-3], expects the output interval type-
2 membership functions to be interval type-2 fuzzy
sets. After the aggregation process, there is a interval
type-2 fuzzy set for each output variable that needs
type-reduction and defuzzification. it is possible, and
in many cases much more efficient, to use a single
spike as the output interval type-2 membership
function rather than a distributed interval type-2
fuzzy set. This is sometimes known as a singleton
output interval type-2 membership function, and it
can be thought of as a pre-type reduction and
defuzzified interval type-2 fuzzy set. It enhances the
efficiency of the type-reduction and defuzzification
process because it greatly simplifies the computation
required by the more general Mamdani method,
which finds the centroid of a two dimensional
functions. Rather than integrating across the two-
dimensional function to find the centroid, we use the
weighted average of a few data points. Sugeno-type
systems support this type of model. In general,
Sugeno-type systems can be used to model any
interval type-2 inference system in which the output
interval type-2 membership functions are either linear
or constant.
Information flows from left to right, from two
inputs to a single output. The parallel nature of the
rules is one of the more important aspects of interval
type-2 fuzzy logic systems. Instead of sharp
switching between modes based on breakpoints, we
will glide smoothly from regions where the system’s
behavior is dominated by either one rule or another.
In the Interval Type-2 Fuzzy Logic Toolbox,
there are five parts of the interval type-2 fuzzy
inference process: fuzzification of the input variables,

6.
Mohit Jha Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 6( Version 2), June 2014, pp.37-47
www.ijera.com 42 | P a g e
application of the interval type-2 fuzzy operator
(AND or OR) in the antecedent, implication from the
antecedent to the consequent, aggregation of the
consequents across the rules, type-reduction and
defuzzification
The implementation of the IT2FLT GUI is
analogous to the GUI used for Type-1 FLS in the
Matlab Fuzzy Logic Toolbox, thus permitting the
experienced user to adapt easily to the use of IT2FLT
GUI. The Mamdani and Takagi-Sugeno-Kang (TSK)
Interval Type-2 Fuzzy Inference Models and the
design of Interval Type-2 membership functions and
operators are implemented in the IT2FLT reused
from the Matlab commercial Fuzzy Logic Toolbox.
B. Next Phase Stage
This stage controls the phase order based on the
length of vehicle's queue and their extension time of
green light from Green Phase Stage. The SIMULINK
block diagram of next phase stage is shown in Figure
4. This stage pick one phase for the green signal and it
extend the green time of the green phase on the basis
of real time traffic condition of the other three phases.
TABLE I. FUZZY LOGIC RULE BASE FOR TRAFFIC CONTROLLER
Rules
Waiting
Time (Wt)
Queue
Length (QL)
Output
1. VS VS Z
2. VS S Z
3. VS L S
4. VS VL S
5. VS EL L
6. S VS Z
7. S S S
8. S L S
9. S VL L
10. S EL L
11. L VS S
12. L S S
13. L L L
14. L VL L
15. L EL L
16. VL VS S
17. VL S S
18. VL L L
19. VL VL VL
20 VL EL EL
21. EL VS L
22. EL S L
23. EL L L
24. EL VL VL
25. EL EL EL
There are four phases in this stage which are
Green light on East direction is phase1, Green light on
West direction phase2, Green light on South direction
phase3, and Green light on North direction phase4.
The real time series is controlled by the triggered
system. Two output of Next phase stage is connected
by switching stage.
C. Switching Stage
This stage switches current phase to the demanded
next phase by output of their previous stage. If any
other way has more vehicle queue length than current
phase to the next phase basis of output of next phase

7.
Mohit Jha Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 6( Version 2), June 2014, pp.37-47
www.ijera.com 43 | P a g e
stage. If the present output of any other phase has
more queue length than the queue length of current
green signal phase. Then the next phase stage give
signal to switching stage to change phase to longer
queue. Code for the switching stage is shown in
Figure 4.
Figure 4 SIMULINK Block Diagram of Light Controller Showing All Three Stages Green Phase, Next Phase And Switching Stage.
D. Emergency Vehicle Controlling
All the other blocks of the traffic controller is
same for the emergency vehicle control system
except that an "embedded MATLAB function block"
which passes an emergency vehicle queue length and
their waiting time to it. This function block has C
coding which continuously check for any emergency
vehicle siren noise signal and will active only of a
particular instant of run time and give maximum
priority to emergency vehicle and then after passing
emergency vehicle it revert back to their previous
stage of real time traffic.

9.
Mohit Jha Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 6( Version 2), June 2014, pp.37-47
www.ijera.com 45 | P a g e
Figure 5(C) Traffic Arrival Process in Lane3
Figure 5(D) Traffic Arrival Process in Lane4
Figure 5(E) Traffic Arrival Process in Lane5
Figure 5(F) Traffic Arrival Process in Lane6
Figure 5(G) Traffic Arrival Process in Lane7
Figure 5(H) Traffic Arrival Process in Lane8
IV. CONCLUSIONS
In this paper, the traffic model and traffic
controller are develop using MATLAB software. This
paper is based on queuing theory model of multiple–
input-single-output. The traffic model is simple to
construct using SIMULINK model and SimEvent
toolbox and IT2FUZZY toolbox in MATLAB. The
traffic controller is developed using fuzzy inference
system method in MATLAB.
To test the effectiveness of this controller here
eight lane different recorded data is considered shown
in Figure 5(A), 5(B), 5(C), 5(D), 5(E), 5(F), 5(G) and
5(H). Also, use certain emergency vehicle data and
test over run time and check the output graph both for
real traffic case and an emergency vehicle case.
Simulation results of green phase switching
shown in Figure 6(A), 6(B), 6(C), 6(D), 6(E), 6(F),
6(G) and 6(H) proves that fuzzy logic interval type 2
traffic controller is superior interval type 1 traffic
controller or to any classical or timing control
methods. In fuzzy logic interval type 1 their
membership functions pass whole values which they
cover in it but in case of interval type 2 they average
passing priority out of all eight lanes and give passing
signal to maximum one. Fuzzy control system
scheme avoids the vehicles waiting in crossing as
much as possible, mitigates the traffic congestion
effectively, improves the intersection vehicle crossing
capacity, efficiency and realizes the intelligent
control of traffic lights. This system is also works